This invention relates to a leg bag accessory that connects a Foley catheter to a leg bag. In particular, it relates to a leg bag accessory that contains an antimicrobial filter and a check valve.
Urinary drainage bag (“leg bags”) attached to indwelling urinary catheters (“Foley catheters”) are commonly used at hospitals and rehabilitation centers on long term and short term patients for incontinence after surgery, chronic disabilities, or other complications. The leg bags are frequently one of the three major sources for an ascending infection that cause urinary tract infections (UTI) in patients. (The other two points of entry are the catheter-leg bag connection and the catheter-skin junction). The leg bags become incubators for bacterial growth, most of which are pathogenic, such as e. coli, p. mirabilis, pseudomonas, Candida, and staph, and frequently antibiotic-resistant strains of those bacteria are present. While the leg bag is intended to keep contaminated urine from reentering the catheter, this nevertheless can occur and is one of the prime sources of UTI in patients.
Each year, more that 30 million urinary catheters are placed in patients in acute care hospitals and extended care facilities. Nosocomial (acquired at home or in nursing homes or hospitals) catheter-associated urinary tract infection (CAUTI) is the most common hospital-acquired infection in acute care hospitals, accounting for 40% of all nosocomial infections. (Stamm, W. E., “Catheter-associated urinary tract infections: Epidemiology, pathogenesis, and prevention,” Am J Med 91 (suppl 3B): 65S–71S, (1991); Burke, J. P. and Riley, D. K., Nosocomial urinary tract infection in hospital epidemiology and infection control. Mayhall, C. G., editor. Baltimore: Williams and Wilkins (1996), pp. 139–153; Maki, D. G., Tambyah, P. A. “Engineering out the risk of infection with urinary catheters,” Emer Inf Dis 7(2)1–5 (2001).) Nosocomial bacteriuria or candiduria develops in up to 25% of patients requiring a urinary catheter for at least 5 days, with a daily risk of 5%. (Stark, R. P. and Maki, D. G., “Bacteriuria in the catheterized patient,” N Engl J Med 311:560–4 (1984)) Catheter-associated urinary tract infection is the second most common cause of nosocomial bloodstream infections. (Maki, D. G., “Nosocomial bacteremia. An epidemiologic overview” Am J Med 70:719–32 (1981); Krieger, J. N. et al., “Urinary tract etiology of bloodstream infections in hospitalized patients,” J Infect Dis 148:57–62 (1983); Bryan, C. S. and Reynolds, K. L., “Hospital-acquired bacteremic urinary tract infection: epidemiology and outcome” J Urol 132:494–8 (1984)) Silent catheter-associated bacteriuria hosts an enormous reservoir of resistant organisms in the hospital which can be spread to other patients on the same units, particularly within ICUs (intensive care units). Studies by Platt and coworkers suggest that although most cases of catheter-associated bacteriuria are asymptomatic, CAUTI appears to be associated with significantly increased hospital mortality. (Platt, R. et al., “Mortality associated with nosocomial urinary tract infection.” N Engl J Med 307(11):637–641 (1982))
Most microorganisms causing endemic CAUTI derive from the patient's own colonic and perineal flora Extraluminal infection may occur early (with in 24–48 hrs of cathetrization) by direct inoculation when the catheter is inserted, or by organisms ascending from the perineum by capillary action in the thin mucous film contiguous to the external catheter surface. (Tambyah, P. A. et al., “A prospective study of pathogenesis of catheter-associated urinary tract infections,” Mayo Clin Proc 74(2): 131–6 (1999).) The intraluminal infection occurs after an average of five to six days from organisms growing in the leg bag reaching the catheter. Numerous strategies to prevent CAUTI have been examined in prospective trials, with the greatest success achieved by the use of sterile closed drainage systems. In a recent trial, use of a silver-hydrogel-coated catheter (Bardex® IC) to reduce the risk of extraluminally-acquired CAUTI was shown to reduce risk 25%, with no effect on the incidence of intraluminally-acquired CAUTIs, however. (Maki, D. G. et al., “A novel silver-hydrogel impregnated indwelling catheter reduces CAUTIs: a prospective double-blinded trial,” Abstract, Programs and Abstracts of the Society for Healthcare Epidemiology in America Annual Meeting; Apr. 5–7 (1998) Orlando, Fla.)
Other measures, such as the daily application of antiseptic solutions or antiseptic ointment to the catheterized meatus or perineum and the addition of antiseptic solutions to the collection bag, have given disappointing results. Bacteria commonly gain access to the collection system. (leg bag) Once colonized, the leg bag becomes a reservoir for bacteria to multiply unchecked and causes infection when contaminated urine refluxes up the catheter into the patient's bladder. Such intraluminal contamination producing CAUTI occurs by a reflux of microorganisms gaining access to the catheter or from failure of closed drainage or by the slow migration of the microorganisms, mostly gram negative from the leg bag to the catheter and to the bladder eventually and accounts for about one-half of CAUTIs.